﻿/*
 * The MIT License (MIT)
 * 
 * Copyright (c) 2012 Junhua
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated 
 * documentation files (the "Software"), to deal in the Software without restriction, including without 
 * limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
 * Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions
 * of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED 
 * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
 * DEALINGS IN THE SOFTWARE.
 */

namespace Avatar.Schedule
{
    using System.Collections.Generic;

    internal class TaskStackContainer : ITaskContainer
    {
        Stack<ITask> stack;

        public TaskStackContainer()
        {
            stack = new Stack<ITask>();
        }

        public ITask Peek()
        {
            return stack.Peek();
        }

        public ITask Pop()
        {
            return stack.Pop();
        }

        public void Push(ITask task)
        {
            stack.Push(task);
        }

        public int Count { get { return stack.Count; } }

        public void Dispose()
        {
            stack.Clear();
        }

        #region IEnumerable<ITask> members

        public IEnumerator<ITask> GetEnumerator()
        {
            if (Count == 0)
            {
                return new List<ITask>().GetEnumerator();
            }

            return stack.GetEnumerator();
        }

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }

        #endregion
    }
}
